Splined gearing



June 10, A19241. I 1,497,274

v W. G. HAWLEY SPLINED GEARING Filed March 25 1924 2 Sheets-Sheet l TTOwww@

.Hume lo, 19%l 1,497,274

` l w. G. HAWLEY SPLINED GEARING 2 Sheets-Sheet 2 VWTNESSES slideaxially along said shaft.

tP/etented .linie .lla-i924. l

Applicatioii'led March 25, 1924. Serial No. 701,706.

` To all whom it may concern: l

Be it known that I, WILLIAM G. HAwLEY, a citizen of the United States,and a resident of Elmira, county of Chemung, and State of New York, haveinvented certain new anduseful Improvements inI Splined Gearing, ofwhich the following is a specification.

This invention relates to that class of gearing in which a gear issuitably mounted upon a shaft so that itmay be readily moved along saidshaft but forced-to rotate therewit/h. Heretofore, this class of gearinghas been constructed in Jvarious forms, each form having vits ownpeculiar drawback. Thus, in the use with a square shaft of a ear havinga bore sufficiently free to permit it to slide axially thereon, it isslow, expensive and almost impossible to accurately grind the squarehole in the gear hub for the purpose of correcting the distortiontherein after said hub has been hardened. Tn another form a roundshaftand slidable gear are `both provided with milled or breached key-ways, akey being inserted in said keyways for holding the gear against rotationon the shaft but permitting said gear to This con-y struction is subject`to several drawbacks. The shaft is weakend by having key-ways cuttherein. When the shaft is hardened by a heat treatment, these key-waysare distorted' and in consequence, when the keys are inserted, thehardened bearing surface on the shaft-is warped. Added to this is thefact that it is a -very diiicult if -not impossible operation toproperly grind the key-ways of small gears like those used forautomobiles, for example. It is desirable that the spline gear and thespline shaft shall have a 4truly cylindrical bearin one upon the otherand also that these earing surfaces shall be hardened.

But the' process of hardening causes more or less distortion or warpingof these cylindrical bearing surfaces, so that some expedient must beemployed for overcoming this difiiculty with a view to producing a truecylindrical surface after hardening. Two

methods have been employed for this pur` pose, namely, one in which'thegear is made to lit uponthe outer diameter of the splines; and the otherin which the gear takes its bearing upon the' portions between thesplines. In the former method according to which the inner` bore of thegear was made to bear directly upon vthe top surfaces of the conditionofthe gears which slide thereon,`

secured. This is due mainly to the fact that the cylindrical portions ofthe bore in the hub of a gear, can be accurately ground under commercialconditions. The shaft can then be made to t the ground bore of the earhub, by properly hardening and grin ing the cylindrical surface thereof.

This grinding operation, however, involvesl the use of peculiarly shapedgrinding p wheels and the provision of specially designed devices formaintaining said grinding wheel in proper shape and in suitable relationto the -work while the operation is in regress.

ne of the provide an improved construction for spline shafts and gearslin which true cylindrical objects of this invention is toA A,

bearing surfaces'v between shaft and gears may be secured' in a simpleand eifectivey manner. f

Another object is to provide a variable speed transmission mechanism1 ofimproved construction and an improved l combination andrelation of partstherein whereby the transmission mechanism can be economicallyconstructed aiid a high degree of precision obtained Vby the employment.of usual shop methods. Toward the attainment lof this object and as anadaptation of the principles underlying the present'invention, theembodiment shown on the drawings includes a spline shaft provided withintegrally formed splines which have been hardened and afterwards roundto a true cylindrical surface :over -t e top surfaces thereof. Mountedon this shaft and having its inwardly presented splines meshing with thesplines on said shaft, is a gear which is provided with axially' spacedinserted bearings which have been machined, hardened and ground, priorto being inserted into said gear. The hardened and round innercylindrical surfaces of these inserted bearings shown in e evation;

Figure 2 is an enlarged fragmentary portion of Figure 1 showing thespline shaft in elevation and certainA hub portions of the gear insection; f

Figure 3 A's a section on the line 3--3, Figure 2, parts being brokenaway and parts shown in elevation, and

Figure 4 is a section on the line 4-4, Figurev 2, parts being brokenaway -and parts shown in elevation.

Referring more particularly to the drawings, a housing 1, is provided atone end witha bearing casing 2. The drive shaft 3 which receives itspower from the engine (not shown) is journalled in axially spaced ballbearings 4 and 5. The inner belled end 6fof the shaft 3 accommodates theball bearings 7 for one end 8 of a spline shaft 9. The other end 8 ofsaid spline shaft is journalledin ball bearings 10 adjacent the otherend of the housing 1. Thebelled end 6 of shaft 3 is provided exteriorl'ywith a rspur gear 11 permanently in mesh with a spur gear 12 keyed tothe countershaft 13 by a key 14. The inner belled end of shaft 3 alsocarries an external spur gear 15 which is adapted to mesh with aninternal spur gear 16 with which an axially movable gear 17 is provided.An exterior spur gear 18 with which the gear 17 is also provided, may

be thrown into and out of mesh with a s ur gear 19 bymeans of suitablegear shifting means (not shown) operating 1n a circular groove 20. Saidgear 19 is keyed to the countershaft 13 by means of a key 21. Axiallyspaced from the gear 17 and internall meshin with the spline shaft, is able .gear llock 22 provided with a circular groove 23 in which suitableear shifting mechanism may operate.- aid gear block comprises a largerspur gear 2li-and a smaller s ur gear 25, the former being adapted to ethrown into and out of mesh with a gear pinion 26 on the countershaft 13and the latter being adapted to` be thrown into and out'of mesh with aspur gear 27 on the countershaft 13. By means of the above describedgears, in connection with the variable driving connections thru thesliding spline gears, the usual selection of speeds may be made.

Mazara Referringvnow to Figures 2, 3 and 4, al

specific description of the spline gear connections between. theleft-hand gear 22 and the spline shaft 9 will serve also for thecorresponding connections between the rightgear and spline shaft as wellas a suitablerconstruction of parts for enabling said bearing surfacesto be ground to a true cylindrical form after they have been hardened bya heat treatment. For this purpose, the top surfaces 33 of the splines9, are turned, hardened and ground to a true cylindrical surface withrespect to the axis o f spline shaft 3. This is a simple grindingoperation which 'may Ybe conducted in the usual well known manner. Inorder to avoid the necessity for grinding the bottoms of the grooves inthe bore of the gear, the hub of said ear, is provided with axiallyspaced cylin rical recesses 28 which may be readily machined and nished.Within said recesses are inserted bearing rings 29, which have beenturned, hardened and ground to true cylindricalsurfaces before theirinstallation in position to serve as axially spaced bear-,

ings for the hardened and ground top surfaces of the splines 9 on thespline shaft.` l

The grinding operation on the hardened bearing rings 29 isa.Y simplecase of cylindrical grindm which ma be accomplished Without diilncu tyin a we l known manner. Suitable-means for releasably securin thecbearing'rings 29 in position within the ubs of gears 17 and 22, may beprovided by springing wire rings 30 into suitable circular grooves 31with which the cylindrical walls of recesses 28 are provided for thispurpose. As shown in F1 ure 3, the ends of wire rings 30 are space apartand provided with' inwardl means of which said ringsvmay be contractedand withdrawn whenever it is desired to do so. The advantages ofthisconstruction are obvious from the above description and brieflyrelated are those resulting from a combination' and relation of elementswhich by reason of their simple form and freely \accessible bearingsurfaces,

turned ends 32 by are adapted to be trued by a simple grinding operationafter being hardened by a heat treatment for the purpose of securing atrue bearing contact permitting an axial movement between a splineshaftand the 'gear in mesh therewith.

1 claim v 1. The combination with a spline shaft, of an internal gearmeshing therewith, said gear being provided with inserted hardened andground bearings in bearing contact'with corresponding bearing surfaceson said spline shaft.

2. The combination with a shaft provided with splines, of a gear havinginwardly presented splines meshing therewith, and bearings separatelyfinished and inserted into said gear, said inserted bearings havingtheir inner surfaces bearing on the top' surfaces of said splines.

3. The combination with a shaft, of a. gear movable axially on saidshaft but nonrotatably connected thereto, and bearings for said gear,said bearings being separately finished and applied to said gear.

4; The combination with a spline shaft, of a gear meshing therewith andmovable ax ially thereof, and separately finished bearings inserted intosaid gear and bearing on the top surfaces of said splines.

5. The combination with a spline shaft of a gear non-rotatably mountedthereon but movable axially thereof, and separately finished-axiallyspaced bearings inserted in the bore of said gear.

6. The combination with a spline gear, of a gear non-rotatably mountedthereon. said gear being provided with recesses adjacent opposite endsof the bore'therein, and bearings inserted in said recesses, saidbearings being providedl with inwardly presented bearing surfacesbearing on the top surfaces of said splines.'

'i'. The combination with a shaft provided with axially extendingsplines hardened and ground on the top surfaces of said splines, of aninternal gear meshing with said splines and provided with axially spacedrecesses in the bore thereof, and separat'ely hardened and groundbearing rings inserted in said recesses and bearing on the tops 'of saidsplines.

8. The combination with a shaft provided with axially extending splineshardened and ground on the top surfaces of said splines of an internalgear .meshing with said splines and provided with axially spacedrecesses in the bore thereof, separately hardene-d and ground bearingrings inserted in said recesses and bearing on the tops of said ysplinesand means for releasably securing said bearing rings in said recesses.

9. The combination of a hardened steel shaft with integral' splineshaving their outer peripheral bearing surfaces 'ound true with respectto the axis of sai shaft,

a gear in mesh with said splines and having inter-tooth spaces of largerdiameter than said bearin surfaces and with axially spaced cylin ricalrecesses coaxial with said shaft, and hardened steel rings seated withinsaid recesses and having inwardly presented bearing surfaces ground truewith respect to the bearing surfaces on said splines.

10. The combination of a shaft with outwardly presented hardened splinesprovided with peripherally ground bearing surfaces trued with respect tothe axis of said shaft, and a gear having axially spaced unbrokenbearing surfaces hardened and ground true with respect to the bearingsurfaces of said splines on which they bear.

11. The combination with a gear having axially spaced internal bearingswhich are hardened and cylindrically ground true with respect to theaxis of said gear, of a shaft with outwardly presented splines withhardened outer peripheries cylindrically ground with respect to the axisof said'shaft andin slidable engagement with said bearings on the gear.

12. The combination of a hardened steel shaft with integral splineshaving their outer peripheral bearing surfaces ground true with respectto the axis of said shaft, a gear having axiallyspaced cylindricalrecesses coaxial .with said shaft, and hardened' steel rings seatedWithin said recesses and having inwardly prentcd bearing surfaces groundtrue with respect to bearing surfaces on said splines.

13. The combination of a shaft with outwardly presented splines providedwith hardened and ground top surfaces and a gear having an inner borelarger than the diameter of the shaft between said s lines and inwardlypresented splines havmg a root diameter greater than the outer diameterof said splines on the shaft, and axially spaced bearing surfaceshardened and ground true with respect to the bearing surfaces of saidsplines on which they bear.

14. The combination with a gear having axially spaced internal bearingswhich are hardened and ground true with respect to the axis of saidgear, of a shaft with outwardly presented bearing surfaces hardened andground true with respect to said internal bearing on the gear, said earbeing non-rotatably connected to said s aft.

WILLIAM G. HAWLEY.

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